In dankelley/argoFloats: Analysis of Oceanographic Argo Floats

Source: oce/sandbox/dek/17_get_local_file/17_get_local_file.Rmd

Abstract. This document, aimed at co-developers and not users, demonstrates the new ability of getIndex() to deal with previously-downloaded files. This relates to issues 584 and 585, and to zoom conversations between me, JH and CR on March 1, 2 and 3 of 2023. One of the changes made in this version is to expand the information provided when debug>0, including timing information. Note in particular that the fastest way to work with a previously-downloaded index is to use the rda file that was created by getIndex() in a previous call. It makes sense to use the OS to rename such a file for safe-keeping, because otherwise a new call to getIndex() will over-write it.

Setup

library(argoFloats)

Save a .gz file for later tests

i <- getIndex(debug=3, keep=TRUE)
i1 <- subset(i, 1)
summary(i1)

Let's also find the name of the file that will later get downloaded.

dataFile <- paste0("~/data/argo/", gsub(".*/", "", i1[["file"]]))

Can we read a previously downloaded .gz file?

Test typical sequence of actions.

GZf <- list.files("~/data/argo", "*.gz", full.names=TRUE)[1]
GZi <- getIndex(GZf, server=NULL, debug=3)
summary(GZi)
GZi1 <- subset(GZi, 1)
summary(GZi1)
unlink(dataFile)
GZp1 <- getProfiles(GZi1)
Sys.time() - file.info(dataFile)$ctime # should be short (just a few Kb download)
summary(GZp1)
GZa1 <- readProfiles(GZp1)
summary(GZa1)

Can we read a previously downloaded .rda file?

Test typical sequence of actions.

RDAf <- list.files("~/data/argo", "*.rda", full.names=TRUE)[1]
RDAi <- getIndex(RDAf, server=NULL, debug=3)
summary(RDAi)
RDAi1 <- subset(RDAi, 1)
summary(RDAi1)
unlink(dataFile)
RDAp1 <- getProfiles(RDAi1)
Sys.time() - file.info(dataFile)$ctime # should be short (just a few Kb download)
summary(RDAp1)
RDAa1 <- readProfiles(RDAp1)
summary(RDAa1)